Circuits for operating lamps using alternating current are known per se. They are in a wide variety of embodiments on the market and are documented in the prior art, for example as electronic transformers for the purpose of operating low-voltage halogen incandescent lamps or as operating circuits for low-pressure discharge lamps, i.e. fluorescent tubes or energy-saving lamps, for example. The latter generally contain a converter for the purpose of producing a radiofrequency supply power for the lamp.
It is furthermore known per se to measure the lamp current during operation, for example in order to regulate this lamp current.